The Bolshoi Ballet’s Art Director Sergei Filin was attacked by an unknown assailant on Thursday in Moscow, suffered severe acid burns to his face.

The attack occurred at around midnight on Thursday, as Filin was approaching his home. A masked assailant called him by name then threw concentrated acid into his face and fled the scene.

Filin was taken to the hospital with third-degree burns to his face and eyes. Doctors are now fighting to save his sight. It could take at least six months for him to recover, with several operations, Bolshoi Theatre spokesperson said.

Police are investigating the attack. The most probable reason is the director's professional activity. Previously, Filin and his family were attacked by phone calls with threats, his car tires were slashed. Shortly before the attack, his Facebook page suffered a hack attempt.

Sergei Filin, 43, a former Bolshoi Ballet star, was appointed Bolshoi Ballet artistic director in March 2011 amid fierce rivalry for the position.